The scheme involves widening a heavily congested 25-mile stretch in East Anglia carrying traffic from the port of Felixstowe to the Midlands.

The Treasury is expected to officially announce the U-turn on tolling today ahead of the launch of the National Infrastructure Plan.

Previously it had insisted the project would be unaffordable without between £300m and £500m from tolling.

But local business leaders had urged against the plan and an influential study last year concluded the A14 upgrade would only relieve congestion if tolling was dropped, warning nearly one in five vehicles would avoid the route if charging was introduced.

After several years of toing and froing over the scheme construction work is now expected to get underway in 2016.

Katja Hall, CBI Chief Policy Director, said: “After so much uncertainty, the news that a decision has been finally made on funding for the A14 means this essential upgrade will get off the ground sooner.

“This will come as nothing short of a relief for businesses given the importance of this trade route to link the port of Felixstowe to the rest of the country.”

A14 Cambridge to Huntingdon Improvement Scheme

• A new dual carriageway southern bypass around Huntingdon extending from the A14 at Ellington to a new junction at Swavesey and extends to the Milton junction on the Cambridge Northern Bypass.
• Widening the A1 between Alconbury to a new junction south west of Brampton
• Widening the existing A14 between the proposed junction at Swavesey to Girton
• Improving the Girton junction
• Widening the Cambridge Northern Bypass between Histon and Milton
• Detrunking the existing A14 through Huntingdon and demolishing the road viaduct